Nannup is a town in the South West region of Western Australia, approximately 280 kilometres (174 mi) south of Perth on the Blackwood River at the crossroads of Vasse Highway and Brockman Highway; the highways link Nannup to most of the lower South West's regional centres. At the 2011 census, Nannup had a population of 587.

The Shire of Nannup is a local government area in the South West region of Western Australia, approximately 280 kilometres (174 mi) south of the state capital, Perth and 60 kilometres (37 mi) southeast of the coastal resort town of Busselton. Its seat of government is the town of Nannup, where about half of the Shire's population reside.